update raiden-contracts to 0.50.1

chore: Pin typing_extensions

chore: Update eth-typing

update raiden-contracts to 0.50.0

Note that the former release candidates anticipated a version `1.0.0rc*`. This
has been changed and the final release of `raiden-contracts` has been made with
version number `0.50.0`.

Also note that in contrast to former update commits for the `arbitrum` branch,
this correctly makes usage of `requirements.in` again and compiles all
dependencies correctly.

update to contracts 1.0.0rc6

fix gas price error margin for arbitrum

update gas estimation, use safety margin for Arbitrum

upgrade to contracts 1.0.0rc5

make dependencies more flexible

cleanup debug logs